package chapter10.Example01;

import java.sql.*;
public class Example01 {
    public static void main(String[] args) throws SQLException{
        /**JDBC连接数据库
         * 1.加载 驱动
         * 2.连接
         * 3.表结构
         * 4.预处理（SQL）
         * 5.结构
         * 6.释放 连接
         */
        /**
         * （1）加载
         * a. 根目录创建lib文件夹
         * b. 将 连接的jar包放入lib
         * c. 点击 文件->项目结构->模块项目结构->模块->依赖->+号->JAP或目录->选中musql的jar包
         * d.编写加载代码
         */
        Statement stmt = null;
        ResultSet rs = null;
        Connection coon = null;
        try{
            // 1.注册数据库驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            // 2.通过DriverManger获取数据库连接
            String url = "jdbc:mysql://localhost:3306/jdbc?sereverTimezone=GMT%2B8&useSSL=false";
            String username = "root";//数据库账户
            String password = "123456";
            coon  = DriverManager.getConnection(url,username,password);
            // 3. 通过Connection对象获取Statement对象
            stmt = coon.createStatement();
            // 4. 使用Statement执行SQL语句
            String sql = "select * from users";
            rs = stmt.executeQuery(sql);
            //5. 显示结果集合
            System.out.println("id   |    name    |    password   |   email    |   birthday");
            while (rs.next()){
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String psw = rs.getString("password");
                String email = rs.getString("email");
                Date birthhday = rs.getDate("birthday");
                System.out.println(id + "  |  "+  name  + "  |  "+ psw +"  |  "+   email   +"  |   "+birthhday);
            }
        }catch (ClassNotFoundException e){
            e.printStackTrace();
        }finally {
            // 6.回收数据库资源
            if (rs != null){
                try {
                 rs.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                rs = null;
                }
            if (stmt !=null){
                try{
                    stmt.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (coon != null){
                try{
                    coon.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                coon = null;
            }
        }
    }
}
